noun
quadratic residue
In number theory, an integer q is a quadratic residue modulo n if it is congruent to a perfect square modulo n.
平方剰余の相互法則は、整数論の基本的な定理の一つです。
The law of quadratic reciprocity is one of the fundamental theorems of number theory.
Compound of 平方 (heihō, 'square') and 剰余 (jōyo, 'remainder, surplus'), directly translating the mathematical concept.